William Overton Gibson was born around 1837 in Albemarle County, Virginia. He moved to Ohio at the age of 17 as a free man with his mother, sisters, and brother. He married Amelia Francis Goins in Athens County, Ohio, around 1860, and they had two children before the war: Lucy A. Hill, born in 1857; and Ezella Tabler, born in 1859.
Gibson enlisted as a private at the age of 27 on August 10, 1864, and mustered in the following day in Marietta, Ohio. His service record describes him as 5 feet, 10 inches tall, with black hair, black eyes, and a black complexion. He served in Company G of the 5th USCT Infantry Regiment. Gibson served during the Siege of Petersburg, including the Battle of the Crater on July 30, 1864. He sustained gunshot wounds to the right forearm and lung in February 1865 at the Battle of Sugar Loaf Ridge in North Carolina. He spent time in the hospital following this wound. Gibson's regiment witnessed the surrender of Confederate General Joseph Johnston at Bennett Place on April 26, 1865. He later mustered out on August 22 in New Bern, North Carolina.
Following the war, Gibson returned to Athens County, Ohio, to live with his family. He had one more child with his wife Amelia: Penn L. Gibson, born in 1871. Amelia died on September 2, 1889, due to injuries sustained in a railroad crash. He then married Eva Jane Norris Hill on August 6, 1894, in Wesley Township, Ohio. Together they had seven children—Mamie, born June 30, 1895; Oliver, born October 4, 1896; Noble, born March 22, 1898; Clyde, born September 16, 1899; Jane, born February 8, 1903; Edgar, born February 16, 1905; and Ason, born August 18, 1908; as well as 3 children who died in infancy. Gibson suffered after the war due to his gunshot wounds. By the time of his death, he succeeded in attaining a pension of $30 per month. Gibson died of rheumatism on July 2, 1911, in Sharpsburg, Ohio. Following his death, his wife Eva applied for a pension but did not receive one. His minor children Oliver, Noble, Jane, Edgar, and Ason, however, each began receiving a $12 monthly pension in 1911.